Heat pump water heaters are gaining broader acceptance as a more economic and ecologically-friendly alternative to electric water heaters. These systems utilize a condenser configured in a heat exchange relationship with a water storage tank, for example wrapped around the tank in a series of coils. During operation of the vapor compression heat pump cycle, air flows across an evaporator and transfers energy to a refrigerant flowing through the evaporator. As such, the refrigerant exits the evaporator as a superheated vapor and/or high quality vapor mixture. Upon exiting the evaporator, the refrigerant enters a compressor where the pressure and temperature increase and the refrigerant becomes a superheated vapor. The superheated vapor from the compressor then enters the condenser, wherein the superheated vapor transfers energy to the water within a storage tank and returns to a saturated liquid and/or high quality liquid vapor mixture.
Certain heat pump water heaters include a shroud positioned over the water tank along the vertical direction. The shroud defines a chamber over the tank, and various components of the heat pump water heater, such as the compressor and evaporator, are disposed within the chamber. The shroud further includes a vent through which air enters the chamber and flows towards the evaporator. However, the airflow provided across the evaporator is frequently non-uniform because portions of the airflow are obstructed by other components, such as the compressor, positioned between the vent and the evaporator.
Accordingly, a heat pump water heater with features for improving airflow across the evaporator would be beneficial.